3 months to resolve billing query

In January I submitted a sponsored billing form to Vodacom. Apparently, due to Vodacom changing systems my form was overlooked but each month I go to them to follow up (as no one will follow up with me). When I ask them what the solution is they tell me to wait some more it will be sorted THIS month (this month has been Feb, March and April and still not resolved) and they tell me to submit an expense claim to my company for call costs incurred, which is ridiculous considering the delay is their fault. Overall experience is very poor including customer service.